1. Field of the Invention
The present invention relates to a toner filling apparatus that fills a container with toner.
2. Description of Related Art
Screw (auger) filling apparatuses have been proposed in order to rapidly fill a container with toner. However, when a screw is rotated at a high speed, toner is subjected to a large stress, which may cause a change in the properties such as occurrence of thermal aggregates. Therefore, such mechanical filling is not favorable.
JP 3547730B proposes a filling method that involves mixing toner with air to fluidize it.
In the invention described in JP 3547730B, after the air content of toner is stabilized in a measuring tank, an eject opening is opened by releasing an eject control member from an elastic ring that forms the eject opening in a sleeve located at the lower end of the measuring tank, so as to let the toner fall down to a small toner container through the eject opening. The aperture of the eject opening is regulated stepwise, and when the loaded toner reaches a specified amount, the eject opening is closed by fitting the eject control member in the elastic ring so as to stop the flow of the toner.
With the invention described in JP 3547730B, since no conveying member or stirring such as a screw is used, toner is subjected to less stress.
Further, in the invention described in JP 3547730B, air in the small toner container is sucked so that toner cloud of suspended toner is removed. For this purpose, a suction pipe is inserted in the small toner container, and only the air is sucked while the loaded toner particles are prevented from passing through the pipe. It is also described that an alternative sucking means may be disposed in the measuring tank (sleeve) instead of the suction pipe.
However, in the invention described in JP 3547730B, since the toner is loaded only by its free fall, the maximum filling speed is limited to a certain level. Furthermore, it takes considerable time to clear away toner cloud of suspended toner by sucking air in the small toner container by using the suction pipe inserted in the small toner container or a sucking means in the measuring tank, which results in the long cycle time of the filling process.